Scaffold hoisting mechanism



Dec. 1s, 1953 R. ALLENBAQGH 2,662,733

SCAFFOLD HOISTING MECHANISM Filed Nov. 6, 1950 f 2 'Sheets-Sheet 1 INVENToR. fa/ph //enaz/gh BM/m- Dec. 15, 1953 R, ALLENBAUGH 2,662,733

SCAFFOLD HOISTING MECHANISM Filed NOV. 6, 1950 2 Sheets-Sheet 2 I INVENTolL 12?(2/,0/9 /P//endz/g Patented Dec. 15,1953

SCAFFOLD HOISTING MECHANISM Ralph Allenbaugh, Mansfield, Ohio, assgnor of one-half to Wilberd F. Feigenbaum, Mansfield,

Ohio

Application November 6, 1950, Serial No. 194,335

3 Claims. l

This invention relates generally to swing stage scaffolds such as are used to support workmen and materials adjacent the exterior of a building or wall while painting or otherwise working thereon. More specifically theinvention relates to a power operated mechanism by which a swing scaffold is supported and is raised and lowered as desired.

According to my invention, the scaffolding is adjustably supported by two spaced single strands of cable which are secured to and extend downwardly from suitable supports which are mounted upon and project outwardly from the top of a building or wall. Each end of the scaffold is suitably secured to a power operated mechanism which in turn is supported by one of the depending cables. The two power operated mechanisms are identical in construction and are adapted to be operated independently of each other. Their construction is such that they climb up or down the ropes or cables when the position of the scaffold is being changed. The mechanisms are power operated in both directions, either up or down.

The principal object of the invention is to provide a power operated scaffold hoisting mechanism which is very efficient in operation and which is of simple construction and relatively in expensive to manufacture.

Another object of the invention is to provide an improved swing stage scaffold which is constructed to be adjustably supported by two spaced single strands of rope or cable.

Another object of the invention is to provide in a power operated scaffold hoisting mechanism improved means by which the hoisting mechanism can be quickly and easily attached to or detached from a supporting cable.

Another object of the invention is to provide a power operated scaffold hoisting mechanism which can be easily attached to and detached from existing swing stage stirrups.

Other and more limited objects of the invention will be apparent from the following speciiication and the accompanying drawings forming a part thereof wherein:

Fig. 1 is a front elevation of my improved swing stage scaffold hoisting mechanism;

Fig. 2 is a side elevation thereof, as viewed from the right of Fig. 1; y

Fig. 3 is a side elevation thereof, as viewed from the left of Fig. 1;

Fig. 4 is a horizontal section, taken on the line 4-4 of Fig. 1;

Fig. 5 is an enlarged detail section, taken on either of the lines 5-5 of Fig. 3, and

Fig. 6 is a vertical section, taken on the line 6-6 of Fig. 5.

Referring now to the drawings by reference characters, the letter A indicates a swing stage plank which is adjustably supported for up and down movement adjacent a wall by a pair of identical hoisting units, one of which is generally indicated by the letter B. The hoisting units B are each removably secured to a depending cable C, each of which cables is secured to an elevated support and hangs down therefrom.

Each unit B comprises a frame I which as shown consists of a flat metal plate to which the entire hoisting mechanism is secured. A stirrup D which supports the plank A is removably secured to the lower end of the frame I by a bolt E which extends through the eye F of the stirrup and an aperture 21 in the frame or plate I. y

Suitably secured to one side of the frame I, as by welding, is a U-shaped bracket 2, the base 3 of which is disposed parallel to the frame I. An anti-friction bearing 4 is removably secured by studs 5 in an aperture 6 in the frame I; and a similar bearing 'I is removably secured by studs 8 in an aperture 9 in the base 3 of the bracket 2, in axial alignment with the bearing 4. A shaft IIJ is rotatably mounted in the aligned bearings 4 and 1, with one end II thereof extending out beyond the frame I on the rside opposite the bracket 2. A worm gear I2 is rigidly secured to the shaft I0 between the bearings 4 and 'I, and meshes with a worm I3 which is keyed to the armature shaft I4 of a reversible motor I5 which is bolted to the frame I as indicated at I6. The outer end of the` armature shaft I4 is rotatably mounted in a bearing II which is removably secured by studs I8 in an aperture I9 in an arm 20 which extends out from the bracket 2. The projecting end of the shaft I4 is squared as shown at 22 for the reception of a hand crank by which the mechanism can be manually operated in the event of a current or motor failure. A drum 23 having end flanges 24, and a tension pulley 25 having an annular groove 26 in the periphery thereof, are keyed onto the projecting end II of the shaft lIIl with the drum 23 adjacent the bearing 4 and frame I. If desired the pulley 25 may be formed integrally with the drum 23. The diameter of the bottom of the groove 26 is the same as the diameter of the drum 23, so that they will both have the same peripheral speed when rotated. An idler pulley 3l), having an annular groove 3| inthe periphery thereof,. is rotatably mounted beneath the drum 23 and pulley 25 onv a shaft or stud 32 which is carried by a bracket 33 suitably secured to the frame I,

'I'he axis of the idler pulley w is disposed at a slight angle to the axis of the drum 23 and pulley 25 for a purpose that will be apparent hereinafter. A pair of similar guide sleeves are carried by arms 36 which are secured to and extend out from the frame I. One guide sleeve 35 is mounted above the drum 23v near the upper end of the frame I and the other guide sleeve 35 is mounted below the idler pulley 30 near the lower end of the frame I. Current is supplied. to the reversible motor I5 from any suitable source through an extension cord- 40'. A switch 4I is provided to control the operation of the motor.

In use the cable C extends down through the upper guide sleeve 35 and then around the drum 23 a plurality of turns. From the drum 23 the cable C extends down and around the idler. pulley 30 and then up and around the pulley 25. From the pulley 25 the cable C extends down through the lower guide sleeve 35. When the motor I5 isA running the drum 23 and the pulley 25 will be rotated in unison through the worm I3, Worm gear I2 and shaft I 0. When running in one direction the cable C is wound onto the drum 23.at the end thereof adjacent the: frame I and is withdrawn from the drum: 23 at, the otherI end thereof by the pulley 25. Since the diameter of; the drum 23 and the diametery of the groove 26 in the pulley 25v in which the cable C runs. are the same,y the cableis withdrawn from drum 23 at the same linear speed that it is Wound onto the drum and is maintained taut upon the drum 23 and pulley 25 at all times. The pull upon, the

cable after it leaves. the drum 2.3 necessary to maintain it taut is very slight, being at the most two or three pounds. When the.- motor I5 is running in the opposite. direction the cable C is; fed by the pulley' 2.5 onto the end ofthe drum 2.3 adjacent the pulley 25 and is withdrawn from theother end thereof. From this.. it will be seen that when the drum 23. and pulley 2.5 are driven in one direction the unit B will, climb. the cable C, andl when the drum 23, and pulley 2;.5 aredriven in the opposite; direction theunit B will climb down the cable C. The construction of the Worm I3 and worm gear I2 with which the worm meshes is such, that they will lock the shaft I0; against rotation when the motor I5. is not running.

To insure that there is no slippagev between the pulley 25 and the cable C. at any time, I. pro.- vide an. idler pressure Wheel 42=Which is springpreed intok engagement with the. cable C. at aDDmxi-mztely the point the cable-C. leaves the pulley 2,5. The wheel 42. isrotatably mounted upon a shaft 43 which isI carried by a` bifurcated arm 44 which is pivotally secured to. a boss. or stud 45 extending out from the. frame- If. A spring 46; having one end thereof secured tov the.v arm 44' by an eye-bolt 4.1 and the other end thereof secured to a stud 46 carried by the. framer I', resiliently. holds the wheel 442 against the: cable C, pressing it tight into the. groove 26 during op.- eratlon. When it is desired to apply the cable C to the unit or to remove ity from the unit, the arm 44 is manually swung about its: pivot into engagement with a stop 48 carried by the boss 45. The spring 46 will then hold the arm 44 against the stop 49.

Inl order to facilitate the application of the cable C to the unit B and itsremoval therefrom, I make each sleeve 35 in two. halfV sections 50 and 5I, with a vertical b ore 52: therethrough which is of substantially the same diameter as the cable C. The lower end 53 of the sleeve which is of lesser diameter than the upper end 54 thereof is inserted in an aperture 55 in an arm 36 and is held therein by a set screw 56. The end of the arm 36 is provided with a slot 51, the Width of which is slightly greater than the diameter of the cable C,y but considerably less than the diameter of' the, aperture 55. To remove the cable C from the unit B the set screws 56 are first loosened and then the sleeves are slid up the cable C out of the apertures 55 after which the halves 50 and 5I are separated and removed` from the cable. The cable is then removed from the apertures 55 through the slots 5l. The cable.` can then be removed from the drum 23. and pulleys 25 and 30. In applying the cable C to the unit B it is first wound around the drum 23 and pulleys 25 and 30 and then inserted through the slots 51 into the apertures 5.5. The sleeves 35 are then placed around the cable above the arms 36 and then moved down into the apertures 5.5 and fastened by the set screws 5.6..

If desired the operating mechanism may be enclosed by a removable cover which will prevent.v workmenfrom getting their hands or clothing caught therein. Such a cover would alsopreventdamage to themechanism by falling articles.

From the foregoing it will be apparent. to those skilled in this art that. I have provided al very simple and eflicient mechanism for accomplishingthe objects of my invention.A

Itis to be understood that IH am not restricted to the specific construction shown. and described hereinasvarious modications may. be made thereto within thesprt, of the invention..`

What isclaimed is:

l. A hoistnmechanism adapted to. moye up and down a suspended cable,A said hoisting mechf anism comprising a frame, a shaft, rotatably sup,- ported by two. spaced bearings carried by said framewith one end of said shaft extending out from one of said bearings, a worm gear securedto said shaft between said bearings, a worm meshing with: said.: worm gear, means for rotating Seid Worm, a drum about. which said cable wound a. plurality of turns,l said drum being secured to the extending end of said shaft, a pulley about which said cable passes. after leaving said drum, said pulley being secured to, said shaft. at One side of said drum., an idler* pulley operative t0 guide said cable from, Said drum and onto said irst mentioned pulley, and means operative. to i-'esmenuy pi-esssaid; @able into engagement with said -rst mentioned pulley.

2. A hoisting mechanism adapted to, move up and. down a suspended cablesad hoisting mech.- anism comprisingd.- a. frame, a shaft. rotatably mounted onsaid frame with the ends of said shait. disposed on onnositesdes of said frame, shaft rotating means carried by said frame and oneratively connected.y to said shaft.y on one side of Saidl frame,- a. drum about. which said suspended cable isadapted to bewound a plurality of turns, said drum being securedy to saidA shaft on the. other sideof said frame. a. tension Ymil/ley operative to withdraw seid; cable. from @noeud of said drum in unison with, the winding o i said cable onto said drum at; the opposite end thereof to thereby. maintain said oable taut. upon said drum, said tension pulley being mounted umn saidI shaft adjacent drum, and anidaler pulley rotatably mounted on said frame in spaced relati-orr to saidV drum and said tension pulley, said idler pulley being independent ofsaid drum and said tension pulley and operative to guide said cable onto said tension pulley after said cable leaves said drum.

3. A hoisting mechanism as defined in claim 2 in which pressure means is provided to resiliently press said cable into engagement with said tension pulley.

RALPH ALLENBAUGH.

References Cited in the file of this patent UNITED STATES PATENTS Number Number Number 10 5,906

Name Date Vickers Sept. 8, 1914 Mendelson Aug. 25, 1931 Holub Feb. 25, 1947 Berchtold Jan. 31, 1950 Niemiec May 16, 1950 FOREIGN PATENTS Country Date Great Britain of 1891 

